In a hospital where a dialysis apparatus subjects a patient to dialysis treatment, a dialysate circuit is cleaned at a required timing such as a time point where one day ends or treatment for one patient ends. Conventionally, a technique for cleaning a liquid circuit by circulating hot water therethrough has been known (e.g., Patent Literature 1).
In an apparatus in Patent Literature 1, hot water heated by a heating device 9 is circulated through the liquid circuit in a state where both valves 21 and 24 are closed after the liquid circuit is filled with a cleaning liquid while a valve 26 in a short-circuit 25, which bypasses an inlet pipe 1 and a return circuit distal end 2, is opened.
However, when the heated hot water serving as the cleaning liquid is circulated through the liquid circuit, air bubbles are generated from the hot water. When air bubbles in a large amount are eventually entrained in a pump, a liquid becomes unable to be fed. As a pump in which such a malfunction occurs, a gear pump and a vane pump have been known. Further, as a dialysis apparatus in which the gear pump is arranged in the liquid circuit, Patent Literature 2, for example, has been known.
If the dialysate circuit in the dialysis apparatus is cleaned by circulating the hot water therethrough, the air bubbles generated from the hot water in the dialysate circuit need to be removed to prevent the pump from being unable to feed a liquid. A conventionally general dialysis apparatus includes a deaeration device for deaerating a dialysate. When the inside of the dialysate circuit is cleaned with the hot water, the air bubbles generated from the hot water are also removed using the existing deaeration device. Such a deaeration device is described in Patent Literature 1 (a deaeration device 10), and is also disclosed in Patent Literatures 2 and 3.